The present invention relates to a radio communication method and a radio communication system including a plurality of wireless terminals in a multihop radio network where data are transferred in such a manner as to pass a bucket or packet from a sending wireless terminal to a receiving wireless terminal via another wireless terminal, and a wireless terminal for use in the radio communication method and the radio communication system.
In a conventional multihop radio network such as a radio sensor network or the like, power consumption in data communication is larger than that in the waiting or stand-by state. However, in terms of a time period, the waiting state occupies most time and the whole power consumption is largely affected by the power consumption in the waiting state. Accordingly, it is essential for each wireless terminal to reduce power consumption in the waiting state as low as possible. In order to realize the reduction of the power consumption, for example, intermittent receive operation has been proposed, as disclosed in Japanese Patent Application laid open No. Sho61-33027 and Japanese Patent Application No. 2003-367577, and low power consumption operation using a clock, as disclosed in Japanese Patent Application No. 2003-109493.
However, when the simple intermittent receive operation is used, although the power consumption can be reduced to some extent, the power is often wasted when traffic is light. On the other hand, when the low power consumption operation using the clock is employed, although the reduction of the power consumption is expected, none of the communications can be done except in communicable time.